Ab-initio study of the structural and electronic properties of osmium under high pressure

Abstract

The structural and electronic properties of osmium (Os) have studied using the full potential linearized augmented plane wave method and the generalized gradient approximation for the exchange-correlation energy. The calculations were done incluiding the spin-orbit (SO) coupling and for hydrostatic pressures up to 400 GPa. The total-energy as a function of the cell volume was computed assuming four different crystal structures, namely hcp, fcc, hcp – ω and bcc. Contrary to previous non-relativistic LDA calculations our study shows that the equilibrium phase of Os correspond to the hcp structure and that remain stable in the studied range of pressures and no structural transition to the fcc, hcp – ω or bcc phases are obtained.